Device for Storage, Transport or Disposal of Objects

ABSTRACT

The invention relates to a device for storage, transport and disposal of objects such as suspected bombs and in particular for objects suspected of containing a so called dirty bomb. The inventive device comprises a shell having a sandwich design with an intermediate layer of lead and outer and inner steel layers. The invention also relates to a method of making such a device.

FIELD OF THE INVENTION

The present invention relates to a device for storage, transport ordisposal of objects such as suspected bombs, in particular objectssuspected of containing radioactive substances or a combination ofexplosives and radioactive substances. The invention also relates to amethod of making such a device and to a method for storage, transport ordisposal of objects such as suspected bombs.

BACKGROUND OF THE INVENTION

Detonation chambers or blast chambers are used to destroy objects suchas for example obsolete ammunition or explosives but also to destroysuspected terrorist bombs in a safe way. The blast chamber or detonationchamber typically comprises a shell that is designed to resist adetonation taking place inside the shell. In use, the object to bedestroyed is placed inside the detonation chamber together with anexplosive charge. The explosive charge is then caused to detonate suchthat the object inside the chamber is destroyed. An example of adetonation chamber is disclosed in, for example, U.S. Pat. No.4,478,126. Design of blast chambers has also been discussed in, forexample, a journal article entitled “Design of Blast Chamber forLong-time use and Experimental Research” by Duan Zhoping and Tong Yi.This article was presented at the “Proceedings of the 2003 InternationalAutumn Seminar on Propellants, Explosives and Pyrotechnics”, Guilin,China.

In recent years, the risk that terrorists will seek to make a so called“dirty bomb” has been discussed. A so called “dirty bomb” is an objectthat contains an explosive charge and one or several radioactivesubstances placed near the explosive charge. If the device is detonated,the explosion will cause the radioactive substance to be scattered overa wide area. A large area can thus become polluted by radioactivesubstances such that the entire area becomes uninhabitable for a verylong period. Additionally, the dirty bomb may cause illness and death toa large number of people who may be exposed to dangerous levels ofradiation before they can be evacuated from the polluted area. Unlike anordinary bomb, a dirty bomb cannot simply be destroyed by an explosivecharge since the radioactive material in the bomb would still remainafter the explosion. If a government agency responsible for securitydiscovers an object that is suspected to be a dirty bomb, it is of vitalimportance that the suspected device can be removed from a place wherethe detonation of a dirty bomb could cause damage. It is moreover highlyimportant that the suspected device can be moved to a place wheredetonation of a dirty bomb would cause the smallest possible damage ordanger to human beings. Since it may be necessary to transport theobject in question through populated areas, it is highly desirable thatthe transport can be carried out safely. It is an object of the presentinvention to provide a device suitable for receiving suspected dirtybombs and which can provide protection against radioactive radiation. Itis also an object of the invention to provide a method of producing sucha device. A further object of the invention is to provide a method fortaking care of suspected dirty bombs.

DESCRIPTION OF THE INVENTION

The invention relates to a safety device comprising a shell that definesa chamber. The shell can be opened and closed such that objects can beplaced inside the chamber. The shell is designed to be able to resist adetonation inside the shell from an explosive charge of up to at least500 g of TNT. The shell is at least partially designed as a sandwichpanel with an inner wall part made of steel, an outer wall part which isalso made of steel and an intermediate wall part that is made of lead.The intermediate wall part is sandwiched between the inner and outerwall parts.

In preferred embodiments of the invention, the shell is a sphericalshell. However, other shapes can also be considered, for examplecylindrical shells.

According to one embodiment of the invention, the intermediate wall partsurrounds only a part of the chamber. In this embodiment, there areopposite sides of the shell that lack the intermediate wall part.

The thickness of the intermediate wall part is suitably 10-30 mm. Theinner wall part may have a thickness of 20-40 mm while the outer wallpart may have a thickness of 5-20 mm.

The invention also relates to a method for disposal of objects suspectedof containing radioactive material. The method comprises providing adevice having a chamber designed to resist a detonation inside thechamber from an explosive charge of up to at least 500 g of TNT, thechamber having a shell which is at least partially designed as asandwich panel with an inner wall part made of steel, an outer wall partmade of steel and an intermediate wall part made of lead, theintermediate wall part being sandwiched between the inner and outer wallparts. In the method, an object suspected of containing radioactivematerial is placed inside the chamber, the chamber is closed and lockedand the device is subsequently transported to a place where detonationof a possible dirty bomb inside the chamber is unlikely to causesignificant damage. For example, it can be placed in a mine shaft.

The suspected object may be tested for radioactivity before it is placedinside the chamber.

The invention also relates to a method of making a shell for theinventive device. The method of making the shell comprises the steps ofproviding a first semispherical shell having wall parts of steel thatare spaced apart from each other to define a gap between the wall partsand pouring molten lead between the spaced apart wall parts to fill thegap with lead, thereby creating a sandwich panel.

Embodiments are possible where the entire semispherical shell is filledwith lead but it is also possible that only a part of the semisphericalshell is filled with lead.

Preferably, the method may further comprise repeating the same stepswith a second semispherical shell and combining the two semisphericalshells to create a spherical shell.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional representation of a deviceaccording to the present invention.

FIG. 2 is a schematic drawing showing how the device may comprise twosemispherical shells.

FIGS. 3 a and 3 b show, from above, a detail of the device according toof FIG. 2.

FIG. 4 is a schematic and cross sectional drawing of a part of the wallof the inventive device.

FIG. 5 is a cross sectional view showing in larger scale a detail fromFIG. 4.

FIG. 6 is a cross sectional and schematic representation of a step in aprocess for manufacturing a device according to the present invention

FIG. 7 is a cross sectional view similar to FIG. 6 but showing asubsequent step in the manufacturing process.

FIG. 8 is a schematic representation of a possible further step duringthe process of disposing of a suspected object.

FIG. 9 is a view similar to FIG. 1 but showing a somewhat differentembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, the invention relates to a safety device 1 forstorage, transport or disposal of an object suspected of containing adirty bomb. The device 1 comprises a shell 2. In FIG. 1, the shell isshowed placed on the ground and standing on legs 16. The shell 2 can beopened and closed such that objects 11, can be placed inside the chamberof the device 1. As indicated in FIG. 2, the shell 2 may be a sphericalshell with two semispherical shells or shell halves 3, 4. The shell 2can then be opened or closed by connecting or disconnecting the halves3, 4 to or from each other. The shell is designed to be able to resist adetonation inside the shell 2 from an explosive charge of up to at least500 grams of TNT (trinitrotoluene). It should be understood that, inmost practical applications, the shell would be designed to resistdetonations from charges of more than 500 grams of TNT. In some cases,it may be suitable to design the detonation chamber to be able to resistup to 1 kg of TNT, or 10 kilos of TNT or even more. The shell 2 is atleast partially designed as a sandwich panel with an inner wall part 5made of steel, an outer wall part which is also made of steel and anintermediate wall part 7 that is made of lead. The intermediate wallpart 7 is sandwiched between the inner 5 and outer wall parts.

If a device is to be used for transport and/or disposal of objects suchas suspected dirty bombs, it is desirable that it be capable ofpreventing radiation from leaking out. Lead which is used for theintermediate layer 7 is a material that is suitable for preventingradiation from escaping through the shell of the chamber. The reason forthis is that lead is a heavy material with a density of about 11350kilos per cubic metre. This makes lead very suitable for stopping bothelectromagnetic radiation and particle radiation that emanates fromradioactive substances. However, lead is a material that is relativelysoft and therefore not so suitable for a shell which is being used tocontain detonations occurring inside the shell. Steel is a materialwhich is far more suitable for this purpose due to the mechanicalproperties of steel, for example the elasticity and tensile strength ofsteel. Steel does not stop radiation as efficiently as lead and if steelis to be used instead of lead for stopping radiation, the steel layerwould have to be thicker than a lead layer having the sameradiation-stopping capacity. For these reasons, the inventor of thepresent invention has found that a device suitable for suspected dirtybombs should have a shell which is based on a combination of lead andsteel. However, the inventor has also found that a steel shell which issimply covered by an outer layer of lead is unsuitable for a chamberwhere it must be anticipated that explosions may occur. The reason isthat detonations taking place inside the steel shell may cause rupturesin the lead cladding and the lead layer is destroyed quite easily. Theinventor has also found that a steel shell that simply uses an internallayer of lead is not a suitable design since fragments from explosionsinside the shell will very easily cause damage to the soft lead layer.However, a shell which is based on a sandwich design with anintermediate layer of lead and inner and outer steel layers can bothresist the destructive forces of a detonation taking place inside thechamber of the safety device 1 and effectively prevent radiation fromleaking out.

The thickness of the intermediate layer may be, for example 10-30 mm. Inmany realistic embodiments, the thickness of the intermediate wall part7 may be 25 mm-30 mm. The thickness of the inner wall parts 5 may be20-40 mm. In realistic embodiments of the invention, the thickness ofthe outer wall part 6 or wall member 6 may be in the range of 5 mm-20mm. The outer wall part 6 can be made less thick than the inner wallpart 5.

The shell 2 is preferably a spherical shell 2 although it is possible touse shells having another shape, for example a cylindrical or cubicalshape. The reason that a spherical shell is preferable is that aspherical shape is believed to be optimal for the ability of the shell 2to resist a detonation inside the shell.

The material used for the inner and outer shells 5, 6 can be steel thathas been cast or hot formed. If the shells 5, 6 are hot formed, theshells 5, 6 can be made of, for example, such steel plates that are soldby SSAB Oxelosund AB, Sweden, under the name Weldox®.

The sandwich design is preferably used for the entire shell. However, itis also possible that only a part of the chamber uses the sandwichdesign. FIG. 9 shows an embodiment where the intermediate wall part 7surrounds only a part of the chamber. The part where the sandwich designis used is designated with the reference numeral 8 in FIG. 1. In theembodiment indicated in FIG. 9, there are opposite sides 9, 10 of theshell 2 that lack the intermediate wall part 7. This means thatradiation can leak out easier through the top part 9 and the bottom part10 of the chamber of the safety device 1. However, the radiation leakingout from these parts will be directed upwards and downwardsrespectively. Hence, a person standing in front of the chamber will notbe so much affected by radiation in these directions.

In FIG. 1 and FIG. 9, a device 13 for measuring radiation isschematically indicated as being placed adjacent the shell 2 andpositioned outside a part 10 of the shell 2 where no intermediate leadlayer is used. If a suspected dirty bomb has been placed inside thechamber, the measuring device 13 can be used to investigate whetherradiation is leaking out from the chamber. It can then be a positiveadvantage that there is a part of the shell where it is easier forradiation to leak out.

As indicated in FIG. 2-FIG. 5, the shell 2 may be provided with alocking ring 17 that can be used to lock the shell parts 3, 4 to eachother. As indicated in FIG. 3 a and FIG. 3 b, the locking ring 17 mayhave teeth 22 adapted to cooperate with teeth 23 in the shell halves 3,4 when the locking ring is rotated. It should be understood that theteeth 23 may be a part of a ring-shaped element 18 connected to eachshell half 3, 4. As indicated in FIG. 4, the teeth 23 in a shell part 3,4 (or ring-shaped element 18) may form a T-profile where the lockingring 17 engages the shell parts 3, 4. As further indicated in FIG. 5,parts of the shell halves 3, 4 that cooperate with the locking ring 17may be provided with ridges 20 that extend into grooves 19 in thelocking ring 17. This design contributes to preventing radiation fromleaking out. It should be understood that parts of the locking ring 17may also be made of lead. As indicated in FIG. 4, the locking ring 17may be surrounded by a ring-shaped outer cover 24 which is substantiallymade of lead. The outer cover 24 may also be a sandwich product with athin inner layer of steel in the form of a metal sheet, an intermediatemain layer of lead and a thin outer layer of sheet metal (preferablysteel). The outer cover 24 may be connected to the locking ring 17, forexample by screws, rivets or by welding. The outer cover 24 forms anadditional radiation barrier that reduces leakage of radiation. However,it should be understood that the outer cover 24 is optional and that itis possible to envisage embodiments without such an outer cover.

As indicated symbolically in FIG. 4, the inventive device 1 may beprovided with one or several seals 29 arranged to seal between thering-shaped element 18 and the locking ring 17. This can contribute toprevent radioactive particles from leaking out. Furthermore, it cancontribute to prevent harmful chemicals from leaking out in case asuspected device should contain harmful chemical substances, for examplepoison gas. The seal 29 may be an inflatable seal.

The invention also relates to the use of the inventive device. Todispose of a suspected object, the object 11 which is suspected ofcontaining radioactive material is placed inside the chamber 1 assymbolically indicated in FIG. 1 and FIG. 2. The suspected object 11 maybe placed in a basket 21 attached to a shell half 3 as schematicallyindicated in FIG. 2. Thereafter, the safety 1 is closed. The closing ofthe safety device 1 is schematically indicated in FIG. 2. In FIG. 2, anopen position of the device 1 is indicated where the upper semisphericalshell part 3 is in a lifted position which is indicated by a broken lineand a closed position is indicated where the upper semispherical shellpart is drawn with an unbroken line. It should be understood that afterclosing of the chamber, the shell halves 3, 4 are locked to each other,for example by the locking ring 17, such that a detonation inside thechamber will not cause the chamber to become open. When the chamber ofthe safety device has been closed and locked, the safety device 1 can betransported to a location that is deemed sufficiently safe.

As previously mentioned, measurement or test of radioactivity may beperformed after the suspected device has been placed inside the chamber.If radiation is detected, it may be decided that the chamber shallremain closed. If no radiation is detected, it can be deemed safe toopen the detonation chamber. It should of course be understood that thesuspected object 11 can also be tested for radioactive activity alreadybefore it is placed inside the chamber of the safety device 1.

As schematically indicated in FIG. 8, disposal of suspected objects canalso include filling the safety device 1 with concrete after a suspectedobject 11 has been placed in the device 1. In FIG. 8, the referencenumeral 27 indicates a conduit through which concrete may enter thechamber 1. When the device 1 is filled with concrete, air may beevacuated through an air pipe 31.

The invention also relates to a method of making the shell 2 of theinventive device. A method of making the shell is schematicallyindicated in FIG. 6 and FIG. 7. The method comprises providing a firstsemispherical shell 3 having wall parts 5, 6 of steel that are spacedapart from each other to define a gap 14 between the wall parts 5, 6. Asindicated in FIG. 6, the wall members 5, 6 or wall parts 5, 6 can beconnected to/fastened to a ring-shaped element 18 which can have, forexample, a T-profile or an H-profile adapted to interact with a lockingring 17 as described above with reference to FIG. 4 and FIG. 5. The wallmembers 5, 6 can be fastened to the ring-shaped element 18 by forexample welding. In FIG. 6, the reference numeral 30 indicates a weldingseam/welding seams. In this way, the wall parts 5, 6 can be held in afixed position in relation to each other to define the gap 14. Asindicated in FIG. 6, the outer wall part 6 may be provided with anopening 25 through which molten lead L can be poured into the gap 14between the wall parts 5, 6 such that the gap 14 becomes filled withlead. Thereby, the intermediate layer of lead is created. Thereby, asandwich panel is created. Possibly, only a part of the semisphericalshell 3, 4 is filled with lead. However, in preferred embodiments of theinvention, the gap 14 between the wall parts 5, 6 is completely filledwith lead. As indicated symbolically in FIG. 7, the opening 25 can beclosed by a plug 26 or some other closing element 26 when the gap 14 hasbeen filled with lead. Alternatively, instead of closing the opening 25,a through-hole can be made in the shell such that a conduit 27 forconcrete can be connected to the shell.

The method may further comprise providing a second semispherical shell 4similar to the first semispherical shell and filling the gap with leadjust as with the first semispherical shell. The semispherical shellparts or halves 3, 4 can then be combined with each other to create aspherical shell 2. The halves can be joined to each other by, forexample, a locking ring 17 as indicated in FIG. 2.

It should be understood that while this description discloses a device,a method for making a shell and a method for disposal of objects, theseare all different aspects of one and the same invention. The inventivemethod is thus suitable for making a shell which can be used for theinventive device. Similarly, the inventive method for taking care ofobjects is suitably carried out with a device according to theinvention.

The inventive device entails the advantage that potentially harmfulobjects can be taken care of in such a way that reduces danger, even ifexplosive devices have been combined with radioactive substances. If anexplosion takes place inside the inventive device, the device can resistthe detonation and significantly reduce the amount of radiation if theexplosive device is combined with radioactive substances. The sandwichdesign makes it more likely that the lead layer will be intact after adetonation inside the inventive device.

The inventive method for making a shell entails the advantage that asemispherical shell with a sandwich design can be manufactured in apractical and effective way.

1-11. (canceled)
 12. A safety device comprising: a shell that defines a chamber that can be opened and closed such that objects can be placed inside the chamber, the shell being designed to be able to resist a detonation inside the shell from an explosive charge of up to at least 500 g of TNT, the shell being at least partially designed as a sandwich panel with an inner wall part made of steel, an outer wall part which is also made of steel and an intermediate wall part that is made of lead, the intermediate wall part being sandwiched between the inner and outer wall parts.
 13. A device according to claim 12, wherein the shell is a spherical shell.
 14. A device according to claim 13, wherein the intermediate wall part surrounds only a part of the chamber and where opposite sides of the shell lack the intermediate wall part.
 15. A device according to claim 12, wherein the thickness of the intermediate wall part is 10 mm-30 mm, the inner wall part is 20 mm-40 mm thick and the outer wall part is 5 mm-20 mm thick.
 16. A method for taking care of objects suspected of containing radioactive material, the method comprising the steps of: a) providing a safety device having a shell that defines a chamber, the shell being designed to resist a detonation inside the chamber from an explosive charge of up to at least 500 g of TNT, the shell further being at least partially designed as a sandwich panel with an inner wall part made of steel, an outer wall part (6) made of steel and an intermediate wall part made of lead, the intermediate wall part being sandwiched between the inner and outer wall parts; b) placing an object suspected of containing radioactive material inside the chamber; c) closing the chamber; and d) locking the chamber such that an explosion inside the chamber will not cause the chamber to become open.
 17. A method according to claim 16, further comprising testing the suspected object for radioactive activity before it is placed inside the chamber.
 18. A method according to claim 16, further comprising filing the chamber with concrete after the chamber has been closed.
 19. A method according to claim 16, further comprising transporting the safety device to a different location after the chamber has been closed and locked.
 20. A method of making a shell for a safety device, the method comprising the steps of: a) providing a first semispherical shell having wall parts of steel that are spaced apart from each other to define a gap between the wall parts; and b) pouring molten lead between the spaced apart wall parts to fill the gap with lead, thereby creating a sandwich panel.
 21. A method according to claim 20, further comprising; c) providing a second semispherical shell having second wall parts of steel that are spaced apart from each other to define a gap between the second wall parts; d) pouring molten lead between the spaced apart second wall parts to fill the gap with lead, thereby creating a second sandwich panel; and e) combining the second semispherical shell with the first semispherical shell to create a spherical shell.
 22. A method according to claim 21, wherein only a part of the semispherical shell is filled with lead. 